Use It or Lose It

Use It or Lose It: Keeping the Brain Young

1

You hear the same complaint all the time as people get older: “My memory is terrible.” Is it all in the

mind, or do real changes take place in the brain with age to justify such grumbling? The depressing answer is

that the brain’s cells, the neurons, die and decline in efficiency with age.

2

Professor Arthur Shimamura, of the University of California at Berkeley, says there are three main ways

in

which

mental

function

changes.

The

first

is

mental

speed,

for

example

how

quickly

you

can

react

to

fast- moving incidents on the road. Drivers in their late teens react quickly but tend to drive too fast, while the

over sixties are more cautious but react more slowly. The near- inevitable slowing with age also partly explains

why soccer players are seen as old in their thirties, while golf professionals are still in their prime at that age.

This type of mental slowing results from a reduction in the efficiency with which the brain’s neurons work.

3

The fact that adults find it harder to learn musical instruments than children points to a second type of

mental

loss with

age

–

a reduction in

learning capacity. The parts of the brain

known as the temporal

lobes

control new learning, and are particularly vulnerable to the effects of aging. This means that as we get older, we

take longer to learn a new language, are slower to master new routines and technologies at work, and we have

to rely more on diaries and other mental aids.

4

“Working memory” is the third brain sy

stem which is vulnerable to the effects of aging. Working memory

is the brain’s “blackboard”, where we juggle from moment to moment the things we have to keep in mind when

solving problems, planning tasks and generally organizing our day-to-day life. Absent- mindedness occurs at all

ages because of imperfections in the working memory system

–

so, for instance, you may continually lose your

glasses, or find yourself walking into a room of your house only to find that you cannot remember what you

came for.

5

Such absent- mindedness tends to creep up on us as we age and occurs because our plans and intentions,

which are chalked up on the mental blackboard, are easily wiped out by stray thoughts and other distractions.

Stress and preoccupation can also cause such absent- mindedness, in addition to age-related changes in the brain.

The

frontal

lobes

of

the

brain

—

located

behind

the

forehead

and

above

the

eyes

－

are

where

the

working

memory

system

is

located.

Like

the

temporal

lobes,

which

handle

new

learning,

the

frontal

lobes

are

more

vulnerable to the aging process than other parts of the brain.

6

The news, however, is not all bleak. Although neurons reduce in number with age, the remaining neurons

send

out

new

and

longer

connecting

fibers

(dendrites)

to

maintain

connections

and

allow

us

to

function

reasonably well with only relatively small drops in ability.

7

This

and

other

evidence

suggests

that

the

pr

inciple

“use

it

or

lose

it”

might

apply

to

the

aging

brain.

Professor

Shimamura

studied

a

group

of

university

professors

who

were

still

intellectually

active,

and

compared their performance on neuropsychological tests with that of others of their age group, as well as with

younger people. He found that on several tests of memory, the mentally active professors in their sixties and

early seventies were superior to their contemporaries, and as good as the younger people.

8

Research on animals provides even stronger evidence of the effects of stimulation on the brain structure.

Professor Bryan Kolb, of the University of Lethbridge in Canada, has shown that animals kept in stimulating

environments show sprouting and lengthening of the connecting nerve fibers in their brains, in comparison with

animal kept in unstimulating environments.

9

The beneficial effects of continued mental activity are shown by the fact that older contestants in quiz

shows

are

just

as

fast

and

accurate

in

responding

to

general

knowledge

questions

as

younger

competitors,

suggesting that at least part of their intellectual apparatus is spared the effects of aging because of practice and

skill.

10

Such

findings

lead

to

the

intriguing

possibility

of

“mental

fitness

training”

to

accompany

jogging

and

workouts for the health conscious. Research in Stockholm by Professor Lars Backman and his colleagues has

shown

that

older

people

can

be

trained

to

use

their

memory

better,

with

the

effects

of

this

training

lasting

several years.

11

Just as people go bald or grey at different rates, so the same is true for their mental faculties. Why this

should be the case for memory and other mental functions is not yet clear, but physical factors play a part. If

Professor Shimamura is right, then the degree to which people use and stretch their mental faculties may also

have a role to play.

By Ian Robertson from

The Times